TY - JOUR

T1 - Hemodynamic significance of coronary jet velocity in patients

T2 - Limitations of the Bernouilli equation in small conduits

AU - Kern, Morton J.

AU - Tron, Christophe

AU - Donohue, Thomas J.

AU - Bach, Richard G.

AU - Caracciolo, Eugene A.

AU - Aguirre, Frank V.

AU - Labovitz, Arthur J.

N1 - Funding Information:
F~om the Department of Internal Medicine, Division of Cardiology, St. Louis University Health Sciences Center. Dr. Christophe Tron is the recipient of a Lavoisier Grant from the French Ministere des Affaires Etrangeres Received for publication May 9, 1994; accepted Aug. 19, 1994. Reprint requests: Morton J. Kern, MD, J.G. Mudd Cardiac Catheterization Laboratory, St. Louis UnLversity Hospital, 3635 Vista Ave. at Grand. Su Louis, MO 63110. Copyright © 1995 by Mosby-Year Book, Inc. ~02-8703/95/$3.00 + 0 4/1/61655

PY - 1995/5

Y1 - 1995/5

N2 - The objective of this study was to assess the use of coronary stenosis velocity in the determination of translesional pressure gradients. In the physiologic assessment of coronary stenosis, the accelerated intracoronary flow velocity within a narrowing has correlated with minimal lesion cross-sectional area according to the continuity equation. In large conduits the jet velocity can determine pressure gradients when used in the Bernouilli equation. However, the use of intralesional flow velocity for calculation of translesional pressure gradients by the simplified Bernouilli equation ({up triangle, filled}P = 4V2) may be inaccurate in small (<5 mm diameter) conduits. Translesional pressure (2.2F catheter) and flow velocity (0.018-inch guidewire) were measured in a single coronary artery in 23 patients undergoing diagnostic angiography or angioplasty. The electronically determined mean of phasic proximal and distal pressure and planimetry of the instantaneous phasic pressure gradient were used and compared with the instantaneous velocity calculations of pressure by the simplified Bernouilli formula with both maximal jet velocity and a modified formula including proximal velocity. The mean measured translesional pressure gradient was 18 ± 13 mm Hg (range 0 to 50 mm Hg) and was equivalent to the instantaneous average pressure gradient by planimetry. The maximal jet velocity was 125 ± 40 cm/sec (range 63 to 250 cm/sec), yielding a calculated pressure gradient of 3 ± 3 mm Hg. The calculated pressure gradient by the simplified Bernouilli equation correlated poorly with the measured translesional gradient (r = 0.27, F = 1.63, p = 0.21). The correlation between stenosis cross-sectional area with flow velocity values and directly measured pressure gradients was weak and neared statistical significance (r = 0.421, F = 4.1, p = 0.057). No correlation was found between the Doppler-derived cross-sectional area and angiographic indexes of stenosis severity. These findings indicate that the intralesional jet velocity cannot be used to estimate translesional coronary pressure gradients.

AB - The objective of this study was to assess the use of coronary stenosis velocity in the determination of translesional pressure gradients. In the physiologic assessment of coronary stenosis, the accelerated intracoronary flow velocity within a narrowing has correlated with minimal lesion cross-sectional area according to the continuity equation. In large conduits the jet velocity can determine pressure gradients when used in the Bernouilli equation. However, the use of intralesional flow velocity for calculation of translesional pressure gradients by the simplified Bernouilli equation ({up triangle, filled}P = 4V2) may be inaccurate in small (<5 mm diameter) conduits. Translesional pressure (2.2F catheter) and flow velocity (0.018-inch guidewire) were measured in a single coronary artery in 23 patients undergoing diagnostic angiography or angioplasty. The electronically determined mean of phasic proximal and distal pressure and planimetry of the instantaneous phasic pressure gradient were used and compared with the instantaneous velocity calculations of pressure by the simplified Bernouilli formula with both maximal jet velocity and a modified formula including proximal velocity. The mean measured translesional pressure gradient was 18 ± 13 mm Hg (range 0 to 50 mm Hg) and was equivalent to the instantaneous average pressure gradient by planimetry. The maximal jet velocity was 125 ± 40 cm/sec (range 63 to 250 cm/sec), yielding a calculated pressure gradient of 3 ± 3 mm Hg. The calculated pressure gradient by the simplified Bernouilli equation correlated poorly with the measured translesional gradient (r = 0.27, F = 1.63, p = 0.21). The correlation between stenosis cross-sectional area with flow velocity values and directly measured pressure gradients was weak and neared statistical significance (r = 0.421, F = 4.1, p = 0.057). No correlation was found between the Doppler-derived cross-sectional area and angiographic indexes of stenosis severity. These findings indicate that the intralesional jet velocity cannot be used to estimate translesional coronary pressure gradients.

UR - http://www.scopus.com/inward/record.url?scp=0029010092&partnerID=8YFLogxK

U2 - 10.1016/0002-8703(95)90108-6

DO - 10.1016/0002-8703(95)90108-6

M3 - Article

C2 - 7732977

AN - SCOPUS:0029010092

VL - 129

SP - 887

EP - 894

JO - American Heart Journal

JF - American Heart Journal

SN - 0002-8703

IS - 5

ER -